WebP Texture Issue in GLB Files: Why It Happens and How to Fix It

What's the Problem?

When you download GLB files generated by AI-based 3D model creation tools (such as Trellis, TripoSR) and try to open them in a 3D application, you may encounter this error:

glTF parsing error: Unsupported extension EXT_texture_webp

This error occurs because the texture files inside the 3D model are stored in WebP format. So why WebP?

What Is WebP and Why Is It Used?

WebP is an image compression format developed by Google. It offers 25-35% smaller file sizes compared to JPEG and provides transparency (alpha channel) support like PNG.

AI 3D model generators prefer WebP format for textures in their GLB files to minimize texture size. This provides:

• Smaller file size → Faster downloads and transfers
• Same visual quality → Minimal detail loss
• Web compatibility → All modern browsers support WebP

glTF and the EXT_texture_webp Extension

glTF (GL Transmission Format) is an open standard file format for 3D models. GLB is the binary version of glTF — it packages all mesh, material, and texture data into a single file.

The standard glTF format only supports JPEG and PNG formats for textures. To enable WebP usage, an extension called EXT_texture_webp was defined. Software that supports this extension can read WebP textures without issues, while unsupported software produces the error above.

Which Software Supports It?

✅ Supported Software

Software	Version	Note
Three.js	r152+	Standard for web-based 3D viewers
Blender	4.0+	Free and open-source 3D editor
Babylon.js	6.0+	Web-based 3D engine
Modern Browsers	Chrome, Firefox, Edge	Via WebGL

❌ Unsupported Software

Software	Note
Windows 3D Viewer	Microsoft's default viewer
Paint 3D	Windows built-in application
Older Blender Versions	3.x and below
Some CAD Software	Industrial CAD tools
Older Game Engines	Non-updated versions

Solutions

1. Use the Right Software

The simplest solution: Use Blender 4.0+. It's free, open-source, and fully supports the EXT_texture_webp extension. Download it from blender.org.

2. Use a Web-Based Viewer

You can view GLB files directly in your browser. Renderhane's built-in 3D viewer uses Three.js r183 and processes WebP textures seamlessly.

3. Download in Alternative Formats

On Renderhane, you can download your 3D model outputs in different formats:

• STL → Geometry-only format, contains no textures. Ideal for 3D printing.
• OBJ → Widely supported format, textures come as separate files.
• GLTF → JSON version of glTF, broader compatibility.

4. Texture Conversion (Advanced)

With Blender 4.0+, you can open the GLB file, convert textures to PNG format, and re-export:

1. In Blender, open the file via File → Import → glTF 2.0
2. Find textures in the Image Editor panel
3. Save as PNG via Image → Save As
4. Re-export via File → Export → glTF 2.0

Does Renderhane Have This Issue?

No. Renderhane's web-based 3D viewer uses Three.js r183 and natively supports the EXT_texture_webp extension. You can view, rotate, and inspect your generated 3D models on the site without any issues.

From the download menu, you can select STL, OBJ, or GLTF formats to get files that work with incompatible software.

Conclusion

The EXT_texture_webp error is a commonly encountered issue as AI-generated 3D models become more widespread. The root cause is that WebP format is relatively new, and not all software has adopted this standard yet. By using the right tools or performing format conversion, you can easily overcome this issue.